The present invention relates generally to surgical retrieval instruments and relates more specifically to a surgical retriever or stone basket in which the tip can be articulated.
Stone baskets for capturing and extracting stones from ureters are well known. Such instruments typically comprise a basket at the forward end of an elongated sheath. Wires disposed within the sheath connect the basket to a handle at the opposite end of the sheath. Various mechanisms for expanding and contracting the basket may be associated with the handle.
Today""s stone baskets and graspers are being used for purposes other than simply capturing a stone in a ureter. They must also be able to reach the kidney, capture a stone, reposition it, remove it, or hold it for adjunctive treatment. Larger baskets can capture larger stones but perform poorly in capturing smaller stones. Known stone baskets cannot readily release a stone if complications arise and there is a need to exit quickly. On occasion, a physician may actually have to cut the basket wires in order to release a stone, which presents the obvious complication of having to extract the basket wires from the patient.
Stated generally, the present invention comprises a medical retrieval device having a handle. An actuator is mounted to the handle for rotational movement. A basket has at least three legs, an adjacent two of the legs being connected to a first location on the actuator radially spaced apart from its axis of rotation. The remainder of the legs are connected to a second location on the actuator radially spaced apart from the axis of rotation such that rotation of the actuator displaces the two legs in a first direction and displaces the remainder of the legs in a second direction different from the first direction. Rotation of the actuator thus articulates the basket
In a disclosed embodiment the medical retrieval device has a hollow sheath attached to and extending forward from the handle. A slide is attached to the handle for longitudinal movement, and the slide is movable along a path between a rearward location and a forward location. The actuator is mounted to the slide for rotational movement. The basket is retracted within a forward portion of the sheath when the slide is in the rearward location, and the basket is extended forward of the forward end of the sheath when the slide is in the forward location. Thus longitudinal movement of the slide extends and retracts the basket, and rotation of the rotary actuator articulates the basket.
In another disclosed embodiment the sheath is attached to the slide such that longitudinal movement of the slide displaces the sheath to cover or to expose the basket.
In the disclosed embodiments the slide assembly is moved along its longitudinal path by the operator applying pressure with his thumb to a button on the top of the slide assembly. In some disclosed embodiments the rotary actuator consists of a drum mounted to the slide for rotation. A thumb wheel is operatively associated with the drum such that rotation of the wheel by the operator""s thumb causes the drum to rotate to articulate the basket.
A special feature of the disclosed embodiment is that, after having grasped a stone, the basket is capable of releasing it. Thus if a physician begins to withdraw a stone and finds it is too large to pass through a physiological constriction such as the intramural ureter, or if complications arise which require rapid extraction of the stone basket, the physician can articulate the basket to spread the basket wires, thereby releasing the stone.
Objects, features, and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the drawings and the appended claims.